A perovskite solar cell based on an ultrafast electron extraction layer and its fabrication method

Abstract

This invention discloses a perovskite solar cell based on an ultrafast electron extraction layer and its fabrication method, belonging to the field of optoelectronic materials and devices. The invention involves spin-coating a hole transport layer onto conductive glass. A precursor solution for the ultrafast electron extraction layer is prepared by combining metal-embedded fullerene molecules with organic polymer materials. This precursor solution is then deposited on a transparent conductive substrate after the perovskite film has been deposited using spin-coating, thus fabricating an electron extraction layer with ultrafast electron transport capabilities. Subsequently, an electron transport material, an interface modification material, and a metal electrode are vacuum-deposited onto the ultrafast electron extraction layer to obtain the perovskite solar cell. The perovskite solar cell fabricated using this ultrafast electron extraction layer exhibits high photoelectric conversion efficiency and excellent device stability, making it suitable for the industrial production of high-efficiency photovoltaic devices.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic materials and devices technology, and specifically relates to a perovskite solar cell based on an ultrafast electron extraction layer and its preparation method. Background Technology

[0002] With societal progress and development, problems such as energy shortages and environmental pollution have become increasingly serious, making the development of clean and renewable energy a global research hotspot. Solar energy, as an inexhaustible and clean energy source, is one of the most promising alternatives to traditional fossil fuels. Solar cells, as the primary technology for converting solar energy into electricity, have received widespread attention in recent years. Currently, mainstream solar cells use crystalline silicon as their main material; however, the production process of crystalline silicon solar cells is energy-intensive, complex, and costly, which limits their further large-scale application in the context of sustainable development.

[0003] In contrast, organic-inorganic hybrid perovskite solar cells have experienced rapid development in recent years due to their simple fabrication process, low cost, and high photoelectric conversion efficiency. Since their first report in 2009, the photoelectric conversion efficiency of perovskite solar cells has increased from 3.8% to over 26%. However, the commercialization of perovskite solar cells still faces many challenges, including device stability and improving electron and hole transport efficiency.

[0004] In perovskite solar cells, the electron extraction layer (ETL) plays a crucial role, efficiently extracting and transporting electrons, reducing charge recombination rate, and thus improving the device's photoelectric conversion efficiency. Currently, commonly used ETL materials include fullerenes and their derivatives (such as PCBM), but these materials still have room for improvement in terms of electron transport rate and interface compatibility with the perovskite layer. Therefore, addressing the problems of slow electron transport rate, poor interface compatibility with the perovskite active layer, and insufficient water and oxygen barrier capacity in perovskite solar cells, leading to low photoelectric conversion efficiency and poor device stability, developing an ultrafast electron extraction layer with ultrafast electron transport capability, good interface compatibility with the perovskite layer, and simple fabrication process is key to further improving the performance of perovskite solar cells. Summary of the Invention

[0005] To address the aforementioned deficiencies in existing technologies, this invention proposes a perovskite solar cell based on an ultrafast electron extraction layer and its fabrication method. A precursor solution for the ultrafast electron extraction layer is prepared by combining metal-embedded fullerene molecules with organic polymer materials. This precursor solution is then deposited on a transparent conductive substrate after the perovskite thin film has been deposited using spin coating, thus fabricating an electron extraction layer with ultrafast electron transport capabilities. Perovskite solar cells fabricated using this ultrafast electron extraction layer exhibit high photoelectric conversion efficiency and excellent device stability. The electron extraction layer possesses outstanding electron extraction and transport capabilities, and its smooth and dense surface provides excellent water and oxygen barrier properties, significantly improving the photoelectric conversion efficiency and device stability of perovskite solar cells.

[0006] The present invention is achieved through the following technical solution.

[0007] One aspect of the present invention provides a method for fabricating a perovskite solar cell based on an ultrafast electron extraction layer, comprising the following steps:

[0008] (1) Clean the etched ITO conductive glass and treat it with ultraviolet ozone to obtain a clean ITO substrate;

[0009] (2) Dissolve the hole transport layer material in an ethanol solution to prepare a hole transport layer precursor solution;

[0010] (3) Dissolve the metal-embedded fullerene and polymer material in chlorobenzene solvent at a mass ratio of 1:(1-50) to prepare an ultrafast electron extraction layer precursor solution;

[0011] (4) Cesium iodide, methylamine hydroiodate, formamidinium hydroiodate, lead iodide, and methylamine lead trichloroisocyanuric acid single crystals were dissolved in a mixed solvent at a molar ratio of (0.05-0.10):(0.05-0.10):(0.90-1.00):(1.00-1.10):(0.05-0.20) to prepare a perovskite precursor solution;

[0012] (5) Spin-coating hole transport layer precursor solution onto cleaned and treated ITO transparent conductive glass to deposit hole transport layer;

[0013] (6) Using the anti-solvent method, the perovskite precursor liquid is deposited on ITO transparent conductive glass with a hole transport layer, and the perovskite film is obtained by annealing.

[0014] (7) The ultrafast electron extraction layer precursor solution is deposited on ITO transparent conductive glass with perovskite film deposited to form an ultrafast electron extraction layer.

[0015] (8) Vacuum thermal evaporation of electron transport material on a thin film with an ultrafast electron extraction layer deposited on it;

[0016] (9) The interface modification material and metal electrode are thermally deposited on the electron transport material to complete the fabrication of perovskite solar cells.

[0017] Preferably, the hole transport layer material is selected from one or more of (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphoric acid, (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid, or [2-(9H-carbazole-9-yl)ethyl]phosphonic acid.

[0018] The metal-intercalated fullerene Nd@C 82 or Nd2@C 82 One or more of them.

[0019] The polymer is selected from one or more of polymethyl methacrylate, polyvinyl chloride, or polypropylene.

[0020] The antisolvent is one or more of anhydrous chlorobenzene, anisole, or ethyl acetate, and the amount used is 0.1 to 0.8 mL.

[0021] Preferably, in steps (2)-(4), the mixture is stirred at 30-120°C for 1-4 hours.

[0022] Preferably, the mixed solvent is prepared by N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1.

[0023] Preferably, the concentration of the perovskite precursor solution is 1.4–2.0 mol / L. -1 ;

[0024] The concentration of the hole transport layer precursor solution is 0.1–10 mg / mL. -1 ;

[0025] The concentration of the precursor solution for ultrafast electron extraction is 1–10 mg / mL. -1 .

[0026] Preferably, in step (6), the annealing is carried out at 100-150°C for 10-100 min.

[0027] Preferably, the electron transport material obtained by thermal evaporation is C. 60 The thickness is 20-50 nm.

[0028] Preferably, the interface modification material is copper bath resin with a thickness of 5-10 nm; the metal electrode is Ag with a thickness of 80-150 nm.

[0029] Another aspect of the present invention provides a perovskite solar cell based on an ultrafast electron extraction layer prepared by the method described above. The prepared perovskite solar cell exhibits excellent interfacial contact between the extraction layer and the perovskite active layer, with a smooth and dense film surface that effectively extracts and transports electrons, reduces charge recombination losses, and also possesses good water and oxygen barrier properties.

[0030] The present invention, by adopting the above technical solution, has the following beneficial effects:

[0031] 1. High-efficiency electron transport: By introducing a metal-embedded fullerene structure, the electron transport capability is significantly improved, ensuring rapid and lossless charge transfer between the perovskite layer and the electrode, and greatly reducing interfacial charge recombination.

[0032] 2. Smooth and dense film surface: The ultrafast electron extraction layer film prepared by using an optimized spin coating method and heat treatment process has a smooth and dense surface, which ensures good interfacial contact with the perovskite layer and enhances the stability of the device.

[0033] 3. Strong water and oxygen barrier: This ultrafast electron extraction layer has excellent water and oxygen barrier capabilities, which can effectively prevent the intrusion of moisture and oxygen in the environment, thereby significantly improving the long-term stability of perovskite solar cells and extending the device life.

[0034] 4. Improved device performance: Perovskite solar cells using the ultrafast electron extraction layer of this invention, fabricated under a nitrogen atmosphere, exhibit excellent photoelectric conversion efficiency and long-term stability, especially under high humidity and high temperature conditions, where the stability of the device is significantly improved.

[0035] The perovskite solar cell based on an ultrafast electron extraction layer prepared by this invention can be applied in the field of optoelectronics. Attached Figure Description

[0036] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, do not constitute an undue limitation of the invention. In the drawings:

[0037] Figure 1 This is a structural diagram of the perovskite solar cell device prepared in a nitrogen atmosphere according to the present invention;

[0038] Figures 2(a) and (b) show the low defect state density, smooth and dense perovskite deposits with C2O2 prepared in a nitrogen atmosphere according to the present invention. 60 Thin films and deposits with C 60 With ultrafast electron extraction layer / C 60 Scanning electron microscope image;

[0039] Figures 3(a) and (b) show the low defect state density, smooth and dense perovskite deposits with C2O2 prepared in a nitrogen atmosphere according to the present invention. 60 Thin films and deposits with C 60 With ultrafast electron extraction layer / C 60 Atomic force microscope image;

[0040] Figure 4 This is a JV curve diagram of perovskite solar cells with and without ultrafast electron extraction layers prepared in a nitrogen atmosphere according to the present invention.

[0041] Figure 5 The present invention presents the photoelectric conversion efficiency over time of perovskite solar cells with and without ultrafast electron extraction layers prepared in a nitrogen atmosphere. Detailed Implementation

[0042] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0043] This embodiment describes a method for fabricating a perovskite solar cell based on an ultrafast electron extraction layer, comprising the following steps:

[0044] Step 1: The etched ITO conductive glass is ultrasonically treated for 30 minutes each in ethanol, ultrapure water with cleaning agent, ultrapure water, and ethanol. The cleaned ITO substrate is then treated with ultraviolet ozone for 30 minutes, dried with nitrogen, and baked in an oven to obtain a clean ITO substrate.

[0045] Step 2: Dissolve (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphoric acid in ethanol and stir at 30–120°C for 1–4 hours to prepare a solution with a concentration of 0.1–10 mg / mL. -1 Hole transport layer precursor fluid.

[0046] Step 3: Add metal-intercalated fullerene (Nd@C) at a mass ratio of 1:(1-10). 82 The polymer material (polymethyl methacrylate) and the solvent (chlorobenzene) are dissolved in the solvent and stirred at 30–120°C for 1–4 hours to prepare a solution with a concentration of 1–10 mg / mL. -1 Ultrafast electron extraction layer precursor solution.

[0047] Step 4: Dissolve formamidinium hydroiodate, lead iodide, cesium iodide, methylamine hydrochloride, and lead chloride in a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1 according to a molar ratio of (0.05-0.10):(0.05-0.10):(0.90-1.00):(1.00-1.10):(0.05-0.20). Stir at 30-120°C for 1-4 hours to prepare a solution with a concentration of 1.4-2.0 mol / L. -1 The perovskite precursor solution.

[0048] Step 5: Take 50 μL of hole transport layer precursor solution and drop it onto the ITO conductive glass treated in Step 1 using a pipette. Spin coat it at a speed of 3000-5000 r / min for 30-50 seconds. Then anneal the ITO coated with hole transport layer precursor solution at 100-150℃ for 10-100 min in a nitrogen atmosphere.

[0049] Step 6: Take 100 μL of perovskite precursor and spin-coat it onto the ITO glass with the hole transport layer deposited in Step 5. The conditions are as follows: spin-coat for 10-30 seconds at a low speed of 1000-3000 r / min in a nitrogen atmosphere; then spin-coat for 30-60 seconds at a high speed of 5000-7000 r / min. At the 30th second from the end, add 0.1-0.8 mL of anhydrous chlorobenzene, anisole, or ethyl acetate as an antisolvent. Anneal at 100-150 °C for 10-100 min in a nitrogen atmosphere.

[0050] Step 7: Take 100 μL of the ultrafast electron extraction layer precursor solution and drop it onto the ITO glass on which the perovskite film was deposited in Step 6 for spin coating. The conditions for spin coating the ultrafast electron extraction layer are: spin coating at 300–500 rpm for 30–60 seconds in a nitrogen atmosphere, without annealing, to form the ultrafast electron extraction layer.

[0051] Step 8: Vacuum thermal evaporation deposition technology is used to deposit an electron transport material C with a thickness of 20-50 nm onto the perovskite thin film obtained in step 7. 60 Thus, the electron transport layer is obtained.

[0052] Figure 1 The diagram shows the structure of the perovskite solar cell device prepared in a nitrogen atmosphere according to the present invention. Figures 2(a) and (b) show the perovskite deposited with C, exhibiting low defect state density and a smooth, dense surface, prepared in a nitrogen atmosphere according to the present invention. 60 Thin films and deposits with C 60 With ultrafast electron extraction layer / C 60 The scanning electron microscope images are shown in Figures 3(a) and 3(b). Figure 3(a) and 3(b) show the low defect state density, smooth and dense perovskite deposits with C2 prepared in a nitrogen atmosphere according to this invention. 60 Thin films and deposits with C60 With ultrafast electron extraction layer / C 60 An atomic force microscope image.

[0053] Step 9: Using vacuum thermal evaporation technology, 5-10 nm copper bath and 80-150 nm Ag metal electrode are deposited on the electron transport layer in step 8 to obtain a perovskite solar cell.

[0054] Figure 4 The JV curves of perovskite solar cells with and without ultrafast electron extraction layers prepared in a nitrogen atmosphere according to the present invention are shown. As can be seen from the figure, the perovskite solar cell with ultrafast electron extraction layer has better performance than the cell without this layer.

[0055] Figure 5 This invention presents the photoelectric conversion efficiency (PCE) over time of perovskite solar cells with and without an ultrafast electron extraction layer, fabricated in a nitrogen atmosphere. The figure shows that the perovskite solar cell with the ultrafast electron extraction layer outperforms the one without.

[0056] The present invention will be further illustrated below through different embodiments.

[0057] Example 1

[0058] This embodiment describes the ultrafast electron extraction layer of the invention and its preparation method in perovskite solar cells, specifically an inverted planar heterojunction solar cell, to provide a full understanding of the invention. The main steps include:

[0059] Step 1) The etched ITO conductive glass was ultrasonically treated in ethanol, ultrapure water with cleaning agent, ultrapure water, and ethanol for 30 minutes each. After drying with nitrogen, it was placed in an oven to bake, resulting in a clean ITO substrate.

[0060] Step 2) Dissolve (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphoric acid in ethanol and stir at 30°C for 4 hours to prepare a solution with a concentration of 1 mg / mL. -1 Hole transport layer precursor fluid.

[0061] Step 3) Add 2mg Nd@C 82 Dissolve 4 mg of polymethyl methacrylate in chlorobenzene and stir at 40°C for 2 hours to prepare a solution with a concentration of 2 mg / mL. -1 Ultrafast electron extraction layer precursor solution.

[0062] Step 4) Dissolve formamidin hydroiodate, lead iodide, cesium iodide, methylamine hydrochloride, and lead chloride in a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1 according to a molar ratio of 0.05:0.08:0.90:1.00:0.1. Stir at 60°C for 2 hours to prepare a solution with a concentration of 1.5 mol / L. -1 The perovskite precursor solution.

[0063] Step 5) Treat the ITO substrate cleaned in Step 1) with ultraviolet ozone for 30 minutes.

[0064] Take 50 μL of hole transport material (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphoric acid and drop it onto the ITO conductive glass treated in step 1) using a pipette. After spin-coating at 5000 rpm for 30 seconds, anneal the ITO coated with (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphoric acid at 100 °C for 100 min in a nitrogen atmosphere.

[0065] Step 6) Take 100 μL of perovskite precursor and dissolve it in the solution. Spin-coat the solution onto the ITO glass with the hole transport layer deposited in Step 5) under the following conditions: spin-coat at 1500 rpm for 25 seconds, 5500 rpm for 40 seconds in a nitrogen atmosphere, add 0.5 mL of chlorobenzene antisolvent at the 30th second from the end, and anneal at 150 °C for 10 min.

[0066] Step 7) Take 100 μL of the ultrafast electron extraction layer precursor solution and drop it onto the ITO glass on which the perovskite film was deposited in Step 6) for spin coating. The conditions for spin coating the ultrafast electron extraction layer are: spin coating at 350 rpm for 50 seconds in a nitrogen atmosphere, without annealing.

[0067] Step 8) Vacuum thermal evaporation is used to deposit 40 nm ICBA on the perovskite thin film obtained in step 7) to obtain an electron transport layer.

[0068] Step 9) Using vacuum thermal evaporation technology, 10nm copper bath and 150nm metal electrode Ag are deposited on the electron transport layer in step 7) to obtain a perovskite solar cell.

[0069] Under standard test conditions (AM1.5G illumination), the solar cell device fabricated in this example exhibits a photoelectric conversion efficiency of 26.78%, an open-circuit voltage of 1.186V, and a short-circuit current of 26.26mA / cm². 2 The fill factor is 85.97%.

[0070] Example 2

[0071] Step 1) The etched ITO conductive glass was ultrasonically treated in ethanol, ultrapure water with cleaning agent, ultrapure water, and ethanol for 30 minutes each. After drying with nitrogen, it was placed in an oven to bake, resulting in a clean ITO substrate.

[0072] Step 2) Dissolve (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphoric acid in ethanol and stir at 60°C for 2.5 hours to prepare a solution with a concentration of 0.1 mg / mL. -1 Hole transport layer precursor fluid.

[0073] Step 3) Nd@C 82 Polymethyl methacrylate was dissolved in chlorobenzene and stirred at 120°C for 1 hour to prepare a solution with a concentration of 1 mg / mL. -1 Ultrafast electron extraction layer precursor solution.

[0074] Step 4) Dissolve formamidin hydroiodate, lead iodide, cesium iodide, methylamine hydrochloride, and lead chloride in a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1 according to a molar ratio of 0.07:0.05:1.00:1.10:0.20. Stir at 30°C for 4 hours to prepare a solution with a concentration of 1.4 mol / L. -1 The perovskite precursor solution.

[0075] Step 5) Treat the ITO substrate cleaned in Step 1) with ultraviolet ozone for 30 minutes.

[0076] Take 50 μL of hole transport material (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphoric acid and drop it onto the ITO conductive glass treated in step 1) using a pipette. After spin-coating at 3000 rpm for 50 seconds, anneal the ITO coated with (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphoric acid at 150 °C for 10 min in a nitrogen atmosphere.

[0077] Step 6) Take 100 μL of perovskite precursor and dissolve it in the solution. Spin-coat the solution onto the ITO glass with the hole transport layer deposited in Step 5) under the following conditions: spin-coat at 3000 rpm for 10 seconds, 7000 rpm for 30 seconds in a nitrogen atmosphere, add 0.3 mL of ethyl acetate as a solvent at the 30th second from the end, and anneal at 120°C for 30 min.

[0078] Step 7) Take 100 μL of the ultrafast electron extraction layer precursor solution and drop it onto the ITO glass on which the perovskite film was deposited in Step 6) for spin coating. The conditions for spin coating the ultrafast electron extraction layer are: spin coating at 450 rpm for 40 seconds in a nitrogen atmosphere, without annealing.

[0079] Step 8) A 20nm ICBA is deposited on the perovskite thin film obtained in step 7) using vacuum thermal evaporation technology to obtain an electron transport layer.

[0080] Step 9) Using vacuum thermal evaporation technology, 9nm copper bath and 80nm metal electrode Ag are deposited on the electron transport layer in step 7) to obtain a perovskite solar cell.

[0081] Under standard test conditions (AM1.5G illumination), the solar cell device fabricated in this example exhibits a photoelectric conversion efficiency of 26.55%, an open-circuit voltage of 1.182V, and a short-circuit current of 26.15mA / cm². 2 The fill factor is 83.85%.

[0082] Example 3

[0083] This embodiment describes the ultrafast electron extraction layer of the invention and its preparation method in perovskite solar cells, specifically an inverted planar heterojunction solar cell, to provide a full understanding of the invention. The main steps include:

[0084] Step 1) The etched ITO conductive glass was ultrasonically treated in ethanol, ultrapure water with cleaning agent, ultrapure water, and ethanol for 30 minutes each. After drying with nitrogen, it was placed in an oven to bake, resulting in a clean ITO substrate.

[0085] Step 2) Dissolve (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphoric acid in ethanol and stir at 100°C for 2 hours to prepare a solution with a concentration of 5 mg / mL. -1 Hole transport layer precursor fluid.

[0086] Step 3) Nd@C 82 Polymethyl methacrylate was dissolved in chlorobenzene and stirred at 80°C for 3 hours to prepare a solution with a concentration of 10 mg / mL. -1 Ultrafast electron extraction layer precursor solution.

[0087] Step 4) Dissolve formamidin hydroiodate, lead iodide, cesium iodide, methylamine hydrochloride, and lead chloride in a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1 according to a molar ratio of 0.10:0.06:0.95:1.10:0.15. Stir at 100°C for 1.5 hours to prepare a solution with a concentration of 1.8 mol / L. -1 The perovskite precursor solution.

[0088] Step 5) Treat the ITO substrate cleaned in Step 1) with ultraviolet ozone for 30 minutes.

[0089] Take 50 μL of hole transport material (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphoric acid and drop it onto the ITO conductive glass treated in step 1) using a pipette. Spin coat it at 4500 rpm for 35 seconds, and then anneal the ITO coated with (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphoric acid at 130 °C for 50 min in a nitrogen atmosphere.

[0090] Step 6) Take 100 μL of perovskite precursor and dissolve it in the solution. Spin-coat the solution onto the ITO glass with the hole transport layer deposited in Step 5) under the following conditions: spin-coat at 2200 rpm for 15 seconds, 6000 rpm for 50 seconds, add 0.8 mL of chlorobenzene antisolvent at the 30th second from the end, and anneal at 100°C for 100 min.

[0091] Step 7) Take 100 μL of the ultrafast electron extraction layer precursor solution and drop it onto the ITO glass on which the perovskite film was deposited in Step 6) for spin coating. The conditions for spin coating the ultrafast electron extraction layer are: spin coating at 300 rpm for 60 seconds in a nitrogen atmosphere, without annealing.

[0092] Step 8) A 30nm ICBA is deposited on the perovskite thin film obtained in step 7) using vacuum thermal evaporation technology to obtain an electron transport layer.

[0093] Step 9) Using vacuum thermal evaporation technology, 8nm copper bath and 100nm metal electrode Ag are deposited on the electron transport layer in step 7) to obtain a perovskite solar cell.

[0094] Under standard test conditions (AM1.5G illumination), the solar cell device fabricated in this example exhibits a photoelectric conversion efficiency of 26.20%, an open-circuit voltage of 1.185V, and a short-circuit current of 25.57mA / cm². 2 The fill factor is 84.67%.

[0095] Example 4

[0096] This embodiment describes the ultrafast electron extraction layer of the invention and its preparation method in perovskite solar cells, specifically an inverted planar heterojunction solar cell, to provide a full understanding of the invention. The main steps include:

[0097] Step 1) The etched ITO conductive glass was ultrasonically treated in ethanol, ultrapure water with cleaning agent, ultrapure water, and ethanol for 30 minutes each. After drying with nitrogen, it was placed in an oven to bake, resulting in a clean ITO substrate.

[0098] Step 2) Dissolve (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphoric acid in ethanol and stir at 120°C for 1 hour to prepare a solution with a concentration of 10 mg / mL. -1Hole transport layer precursor fluid.

[0099] Step 3) Nd@C 82 Polymethyl methacrylate was dissolved in chlorobenzene and stirred at 30°C for 4 hours to prepare a solution with a concentration of 8 mg / mL. -1 Ultrafast electron extraction layer precursor solution.

[0100] Step 4) Dissolve formamidin hydroiodate, lead iodide, cesium iodide, methylamine hydrochloride, and lead chloride in a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1 according to a molar ratio of 0.10:0.10:0.90:1.00:0.20. Stir at 120°C for 1 hour to prepare a solution with a concentration of 2.0 mol / L. -1 The perovskite precursor solution.

[0101] Step 5) Treat the ITO substrate cleaned in Step 1) with ultraviolet ozone for 30 minutes.

[0102] Take 50 μL of hole transport material (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphoric acid and drop it onto the ITO conductive glass treated in step 1) using a pipette. After spin-coating at 3500 rpm for 40 seconds, anneal the ITO coated with (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphoric acid at 120 °C for 80 min in a nitrogen atmosphere.

[0103] Step 6) Take 100 μL of perovskite precursor and dissolve it in the solution. Spin-coat the solution onto the ITO glass with the hole transport layer deposited in Step 5) under the following conditions: spin-coat at 1000 rpm for 30 seconds, 5000 rpm for 60 seconds in a nitrogen atmosphere, add 0.1 mL of anisole antisolvent at the 30th second from the end, and anneal at 130 °C for 60 min.

[0104] Step 7) Take 100 μL of the ultrafast electron extraction layer precursor solution and drop it onto the ITO glass with the perovskite film deposited in Step 6) for spin coating. The conditions for spin coating the ultrafast electron extraction layer are: spin coating at 500 rpm for 30 seconds in a nitrogen atmosphere, without annealing.

[0105] Step 8) A 50 nm ICBA is deposited on the perovskite thin film obtained in step 7) using vacuum thermal evaporation technology to obtain an electron transport layer.

[0106] Step 9) Using vacuum thermal evaporation technology, a 5nm copper bath and a 120nm metal electrode Ag are deposited on the electron transport layer in step 7) to obtain a perovskite solar cell.

[0107] Under standard test conditions (AM1.5G illumination), the solar cell device fabricated in this example exhibits a photoelectric conversion efficiency of 25.57%, an open-circuit voltage of 1.18V, and a short-circuit current of 26.78mA / cm². 2 The fill factor is 85.02%.

[0108] As can be seen from the above embodiments, the solar cell device prepared by the present invention has a photoelectric conversion efficiency of not less than 25.57%, an open-circuit voltage of 1.186V, and a short-circuit current of not more than 26.78mA / cm². 2 The fill factor is not less than 83.85%. It has excellent electron extraction and transport capabilities, and its smooth and dense surface has good water and oxygen barrier capabilities, which greatly improves the photoelectric conversion efficiency and device stability of perovskite solar cells.

[0109] This method significantly improves electron transport rate, enhances interface compatibility, and strengthens the long-term stability of the device. This invention prepares an ultrafast electron extraction layer precursor solution by combining a metal-embedded fullerene with an organic polymer material. This precursor solution can be deposited on the surface of a perovskite thin film using a spin-coating process to form a smooth and dense ultrafast electron extraction layer. This extraction layer can efficiently extract and transport electrons, reducing charge recombination losses. Simultaneously, its dense film structure provides excellent water and oxygen barrier capabilities, significantly improving the environmental stability of the device.

[0110] This invention is not limited to the above embodiments. Based on the technical solutions disclosed in this invention, those skilled in the art can make some substitutions and modifications to some of the technical features without creative effort, and all such substitutions and modifications are within the protection scope of this invention.

Claims

1. A method for fabricating a perovskite solar cell based on an ultrafast electron extraction layer, characterized in that, Includes the following steps: (1) Clean the etched ITO conductive glass and treat it with ultraviolet ozone to obtain a clean ITO substrate; (2) Dissolve the hole transport layer material in an ethanol solution to prepare a hole transport layer precursor solution; The hole transport layer material is selected from one or more of (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphoric acid, (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid, or [2-(9H-carbazole-9-yl)ethyl]phosphonic acid; (3) Dissolve the metal-embedded fullerene and polymer material in chlorobenzene solvent at a mass ratio of 1:(1-50) to prepare an ultrafast electron extraction layer precursor solution; The metal-intercalated fullerene is selected from Nd@C 82 or Nd2@C 82 One or more of them; The polymer is selected from one or more of polymethyl methacrylate, polyvinyl chloride, or polypropylene; (4) Cesium iodide, methylamine hydroiodate, formamidinium hydroiodate, lead iodide and methylamine lead trichloroisocyanuric acid single crystals were dissolved in a mixed solvent at a molar ratio of (0.05-0.10):(0.05-0.10):(0.90-1.00):(1.00-1.10):(0.05-0.20) to prepare a perovskite precursor solution; (5) Spin-coating hole transport layer precursor solution onto cleaned and treated ITO transparent conductive glass to deposit hole transport layer; (6) Using the anti-solvent method, the perovskite precursor liquid is deposited on ITO transparent conductive glass with a hole transport layer, and the perovskite film is obtained by annealing. The antisolvent is one or more of anhydrous chlorobenzene, anisole, or ethyl acetate, and the amount used is 0.1~0.8 mL; (7) The ultrafast electron extraction layer precursor solution is deposited on ITO transparent conductive glass with perovskite film deposited to form an ultrafast electron extraction layer. (8) Vacuum thermal evaporation of electron transport materials on thin films with deposited ultrafast electron extraction layers; (9) The interface modification material and metal electrode are thermally deposited on the electron transport material to complete the preparation of the perovskite solar cell.

2. The method for fabricating a perovskite solar cell based on an ultrafast electron extraction layer according to claim 1, characterized in that, In steps (2)-(4), the mixture is stirred at 30~120 ℃ for 1~4 hours.

3. The method for fabricating a perovskite solar cell based on an ultrafast electron extraction layer according to claim 1, characterized in that, The mixed solvent is prepared by N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:

1.

4. The method for fabricating a perovskite solar cell based on an ultrafast electron extraction layer according to claim 1, characterized in that, The concentration of the perovskite precursor solution is 1.4~2.0 mol L. -1 ; The concentration of the hole transport layer precursor solution is 0.1–10 mg / mL. -1 ; The concentration of the precursor solution for ultrafast electron extraction is 1~10 mg / mL. -1 .

5. The method for fabricating a perovskite solar cell based on an ultrafast electron extraction layer according to claim 1, characterized in that, In step (6), anneal at 100~150 ℃ for 10~100 min.

6. The method for fabricating a perovskite solar cell based on an ultrafast electron extraction layer according to claim 1, characterized in that, The electron transport material obtained by thermal evaporation is C. 60 The thickness is 20~50 nm.

7. The method for fabricating a perovskite solar cell based on an ultrafast electron extraction layer according to claim 1, characterized in that, The interface modification material is copper bath, with a thickness of 5-10 nm; the metal electrode is Ag, with a thickness of 80-150 nm.

8. A perovskite solar cell based on an ultrafast electron extraction layer prepared by the method according to any one of claims 1-7.

9. The perovskite solar cell based on the ultrafast electron extraction layer according to claim 8 is used in the field of optoelectronics.

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